ohio state’s high-rise residence hall renovations with geothermal well field

Ohio State’s High-Rise Residence Hall Renovations with

Geothermal Well FieldTom Reeves, Director

Jeffrey Roe, Senior Energy Engineer

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Business Reasons:Quarters to Semester Switch

-Late September through mid-June-Now: Mid August move-in (HOT!)

Additional capacity needed

Office of Student Life

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This project added ~250 new beds and renovated the spaces for ~2150 existing beds.These residence halls now have air conditioning, new restrooms, new lobby spaces and courtyard


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West: ~1900

South: ~5900

North: ~4100 (~7000 in Autumn 2017)

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“South High-Rise” (SHR for short)These are 5 individual 11 story buildings built in the 1950s – heating only without outside air. Rooms designed for doubles and triples with corridor bathrooms

Typical old floor plan:

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Major renovation included:1. Insulation – Walls ~R3 to ~R182. Air Conditioning – Using “Valence” units. 3. Upgraded windows - operable aluminum frame4. Privatized Bathrooms 5. Additional Programming Space

(Study Rooms, Lounges, Courtyard)

Typical new floor plan:

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264 wells, 3 vaults

145 wells, 1 vault

Plant “Bunker” location

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Move in Day 2013This is the second year for Park-Stradley (pictured)

This is the first year for Smith-Steeb and Siebert


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Design Decisions - GeothermalPros of Geothermal System:1. Expected long lifespan of energy savings2. Upfront costs relatively low due economic conditions at

the time3. GREAT PR

Cons:4. Requires fencing off significant green space for several

years for construction


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Marketing Material

Posters on fencing around construction


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Full slide picture

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Full slide picture

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Geothermal Well Field Design• 411 wells at 550 feet deep• 4 underground “vaults” for isolating branches of wells

• (7-13 wells/branch)

• Plastic piping used, tracing wires

• Designed for 1500 tons of cooling, expecting more for heating.


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Full slide picture

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Design Decisions - Fan-Coils vs. ValancePros of Valance Units:1. No fan – no electrical use (other than valve)2. No filter3. No floor space loss4. No refrigerant near student quarters

Cons:5. Takes up ceiling space6. May require higher water temperatures to provide

circulation to heat the room – 150F recommended by our design engineer


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ValanceComputational Fluid Dynamic Model


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ValanceCFD Model


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Design Decisions - Large Heat PumpsReasoning:1. We used this system on a much smaller installation, the

510 person dorm “Residence on 10th, which received LEED Gold.

2. Residence on 10th has been operating satisfactorily• The output of the chillers is only 130F here, where fan coils

are used, which allowed for different choices in heat pump selection


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Design Decisions - Large Heat PumpsRequirements:1. Large equipment allows for refrigerant risk mitigation –

minimal HVAC refrigerant lines near student areas2. Condenser side must be able to produce 150F water for

best operation of the valance1. This requirement drove the decision to between two pieces of

equipment1. York CYK 2. Multistack Packaged Scroll

3. Steam remains as backup system


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York CYKPro•Small footprint

Con•Limited turndown, especially heating mode


MultistackPro•Better turndown / part loading

Con•Large footprint (many units needed)

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York CYKChosen for smaller footprint

Constant 42F/150F or floating either point


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Full slide picture

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WindowsTriple Glazed, Low E

South and WestSHGC: 0.24U-Value: 0.12 = R-Value of 8

North and EastSHGC: 0.35U-Value: 0.12 = R-Value of 8


½ slide picture

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Design Decisions - Other Considerations• 2-Pipe risers – Only heating or cooling provided

• Did not include bypass at end of each loop – dead ends, but valance units flush this water within a few minutes.

• Lack of simultaneous heating and cooling uses far less energy• Outside air to hallways and out bathrooms

• No direct outside air to student rooms – requires operable windows.

• Window sash sensors not installed – no ability to cut cooling/heating out with windows open.


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Full slide picture

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2012-2013 School Year ResultsPark-Stradley was lived in. Plant provided heating and cooling to Smith-Steeb and Siebert as well, as they were under renovation.1. Plant Steam (York CYK not running until spring): 13,700

x 10^6 BTU2. Plant kWh: 1.5M kWh3. Park-Stradley kWh: 1.7M kWh4. Smith-Steeb and Siebert kWh (under construction):

1.0M kWh


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7/30 8/4 8/9 8/14 8/19 8/24 8/29 9/3 9/80

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Complex's Ton-Hrs from Plant and Outside Temperature

Ton-

Hrs

Degr

ees F

2400 Students No Students

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Example Operating Points – 11:30 9/4/13• Commissioning is NOT complete yet• Student Capacity Cooled: 2400 students• OAT: 71F• Chiller EEFT/ELFT/Flow 49.6/43.3/1370 (360 tons)• Chiller kW / kW/ton 788kW / 2.2 kW/ton

• Secondary Chilled Water • SCWS / SCWR / Flow: 46/50/2060 (backflow in bypass

sends warmer water to valances, which work fine at higher temperatures)


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Future Plans• We have (3) 800 ton heat-pump chillers and the existing

load appears to max at out about 550 tons for cooling. • Heating load is unknown, but it appears to also be much

below the available (3) 13.3M Btu/Hr units. • We have added piping to send heat to existing heating

hot water only low rise buildings nearby – ready for this winter


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No Students

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Lessons LearnedKeep mechanical rooms above sewer level

Water main burst, flooding the chiller bunker. Much equipment needed rebuilt/replaced.


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Questions?

Contact• Jeffrey Roe, [email protected], 614-623-6048


mailto:[email protected]

ohio state’s high-rise residence hall renovations with geothermal well field

Documents

siebertoffice of student

office of student life

student areascondenser

student quarters cons

design decisions fan

new beds

new restrooms

geothermal system